Electric time piece contact mechanism



06L 1960 F. KOEHLER 2,956,142

- ELECTRIC TIME PIECE CONTACT MECHANISM Filed Aug. 15, 1958 x 2'6 za 2.2

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Fred Koe/v/er INVENTOR.

United States Patent ELECTRIC TIME PIECE CONTACT NIECHANISM Fred Koehler, Lancaster, Pa., assignor to Hamilton Watch Company, Lancaster, Pa., a corporation of Pennsylvania Filed Aug. 15, 1958, Ser. No. 755,280

2 Claims. (Cl. 200-166) This invention relates to a battery operated electric time piece and more particularly relates to the contact mechanism of a battery operated electric time piece having a combined index and contact mechanism.

In the type of battery operated time piece shown in assignees Patent No. 2,662,366 to Fred Koehler, the motivating power is supplied by periodically energizing a pair of electro-magnets to impulse a magnetic bar carried by the balance staff. The energization of these electromagnets is elfectuated by a contact system which is combined with the indexing system, so that movement of the index wheel controls the contact making operation.

As is described more fully in the aforementioned Koehler patent, an elongated spring contact arm extends past the toothed index wheel and this wheel periodically receives a mechanical impulse from the balance staff through a mechanism carried by the balance stalf. This elongated contact arm carries contacts at one end and is fixed to the watch framework at the other end. Intermediate its ends it carries a cam which engages the teeth of the index wheel for two purposes. The cam, on the one hand, holds the index wheel in position between mechanical impulses from the balance staff, and, on the other hand, the cam forces the contact spring outwardly upon movement of the index wheel to effectuate the contact making.

In the early models of this time piece the cam, which may be a jewel or which may be formed of suitable metals such as carboloy, was attached to the contact spring by cementing. This method of assembly, however, presented certain difiiculties both in the placement of the cam and in thereliability of the attachment of the cam to the contact spring.

It is accordingly a primary object of the present invention to provide an improved contact system for an electric time piece.

It is another object of the invention to provide an improved contact system for an electric time piece of the type wherein the contact system performs the dual function of making contact and assisting in the indexing of. the time piece characterized by an improved assembly of the indexing cam to the contact spring.

It is still another object of the invention to provide in an electric time piece utilizing a combined indexing and contact system an improved cam and contact spring assembly which facilitates accurate, economical and reliable attachment of the cam to the contact spring.

These and further objects and advantages of the invention will become more apparent upon reference to the following specification and claims and appended drawings wherein:

Figure 1 is a partial plan view of a contact spring shown prior to the time that the mechanism for holding the cam is bent into its final position;

Figure 2 is a partial side elevation of the contact spring of Figure 1 showing the cam holding mechanism bent into its final position; 1

Figure 3 is a partial plan view of the contact spring of and Figure 4 is a partial plan view of another embodiment of a contact spring shown prior to the time that the cam holding mechanism is bent into its final position.

The contact spring and cam assembly which is the sub ject of this invention is intended for use in an electric time piece of the type generally shown in Koehler Patent No. 2,662,366 and reference may be had to that patent for a detailed description of the time piece itself. Referring to Figure 1, the contact spring assembly is formed from a flat elongated spring 10 which carries a series of contacts 12 on fingers 14 at its end, as in the afore mentioned patent. This spring arm is initially stamped from spring metal and at that time is provided with a pair of opposed ears 16 having holes 18 therein. In order to secure a D-shaped cam to the contact spring, the ears 16 are bent upwardly perpendicular to the plane of the spring 10,-as shown in Figure 2, and a D-shaped jewel or other suitable cam 20 is inserted into the holes 18. The resiliency of the spring metal is such that the ears 16 tend to spring outward thereby locking the cam 20 in position.

According to another embodiment of the invention shown in Figure 4, a wider fiat contact spring 22 carrying contacts 24 has stamped therein two opposed U-shaped cuts 26. Concentrically located within these cuts are a pair of opposed holes 28. In the assembly of the cam to this contact spring, the tabs or ears formed by the U-shaped cuts 26 are bent upwardly and the cam is inserted in the then aligned holes 28. As in the preceding embodiment of the invention, the resiliency of the spring metal clamps the cam in position.

It will be apparent from the foregoing, that the accuracy of placement of the cam may be fixed by means of the die which cuts the contact spring thereby insuring perfect identity of all contact springs. The cam insertion step is extremely simple and the attachment of the cam to the contact spring is completely reliable. Not only is increased accuracy and reliability obtained, but the labor and time involved in the operation is also reduced.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. In a contact apparatus for an electric time piece, an elongated flat spring carrying contact means at one end, a pair of cars formed integrally with said spring and extending away from the plane thereof intermediate the ends of said spring, said ears having holes therein, and a D-shaped cam mounted in said holes with the fiat surface of said D-shaped cam contacting and resiliently held by said pair of ears.

2. In a contact apparatus for an electric timepiece, an elongated fiat spring carrying contact means at one end, a pair of cars formed integrally with said spring and extending away from the plane thereof intermediate the ends of said spring, said ears having holes therein, and a cam member extending across said elongated flat spring and having one surface thereof in engagement with said spring, said cam member extending into said holes in said ears whereby said ears resiliently hold said contact member against said elongated flat spring.

(References on following page) References Cited in the file of this patent UNITED STATES PATENTS Hoge Dec. 1, 1925 Hallenbeck Sept. 13, 1932 Stewart Apr. 25, 1933 4 Spencer Feb. 10, 1948 Udale May 24, 1955 Gallagher et a1 July 8, 1958 FOREIGN PATENTS Great Britain Sept. 2, 1929 

